Tribological characteristics of aluminum-50 Vol Pct graphite composite

Abstract

Friction and wear in composites containing 50 vol pct granular or flake graphite in 2014 aluminum alloy have been measured for different normal loads and sliding velocities ranging from 25 to 100 N and 0.5 to 3 m/s, respectively. The coefficients of friction and wear are significantly lower in the composites, as compared to those in the matrix alloy containing no graphite. The transition to severe wear takes place at a higher load and sliding velocity as compared to the base alloys, particularly in composites containing granular graphite. In composites containing flake graphite, friction and wear depend on sliding direction relative to the orientation of the flake. This behavior has been explained on the basis of subsurface deformation, leading to transfer of graphite to the tribosurfaces, and the plastic flow of constituent alloy, resulting in covering of the embedded graphite by the matrix alloy. © 1993 The Minerals, Metals and Materials Society, and ASM International.